ES2964171T3 - Cooler body - Google Patents

Abstract

The invention relates to a cooling body (1), in particular designed for cooling an electronic element (100), comprising a contact piece (2), comprising a contact surface for contact with the part to be cooled (100), a base piece (3) separated from the contact piece (2) by an intermediate piece (4) in the middle. The intermediate piece (4) comprises separate holes forming parallel arranged coolant tubes (5d, 5u, 5d1, 5u1, 5d2, 5u2-5dN), whereby each tube (5d, 5u) extends from the contact piece (2) to the base piece. (3) and at least two coolant channels (C, C1-Cn) are formed by a sequence of parallel tubes (5d, 5u) connected by an envelope surface (2s) of the contact piece (2) and an envelope surface (3s) of the base piece (3) such that the coolant channels (C, C1-Cn) run several times from the contact piece (2) to the base piece (3) and vice versa. (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Cooler body

field of invention

The present invention relates to a cooling body which, in particular, is adapted to cool structural units or electronic assemblies.

Background of the invention

As is known, power dissipation and therefore heat evolution of electronic modules increase with the development of electronic structural elements as a function of power. It is true that these components are becoming smaller, but their efficiency and, therefore, the heat to be removed increase. Furthermore, due to their compactness, these electronic elements are placed in a smaller space, so that again a greater local heat development occurs. The achieved power dissipations would only be possible with complicated and bulky cooling bodies in case of fan cooling and are therefore unacceptable. In case of large losses, therefore, air cooling clearly reaches its limits.

The new high-performance processors offer between 70 and 100 W in an area of about 10 cm2 and thus achieve a much higher heat flow density. Processor manufacturers predict that a further increase in waste heat is expected in the coming years. In view of this development, those skilled in the art are considering liquid cooling for such applications. Liquid cooling more effectively dissipates heat from electronic assemblies, with the result that higher power density is possible. Liquid coolers also allow for more compact switch cabinets with numerous electronic components and operate very quietly.

An exemplary generic cooling apparatus is disclosed in EP 2291 859 A1, in which an insert is provided within a cooling channel, the insert having a plurality of pins forming channels towards a cooler wall and being supplied with coolant through openings in an inclined surface of the inlet that is struck by a flow of coolant from the coolant channel.

Specifically in the field of power electronics in automotive applications, more specifically for inverter devices, converters and chargers for electric vehicles, intense cooling of the electronic components is necessary, especially switching components such as IGBT or MOSFET (already that these are the components with the greatest amount of energy loss in said devices and, therefore, are the main sources of heat within them). US 2017/0092565 A1 discloses a heat transfer microarray for cooling semiconductor devices, the array may comprise microjets, microchannels, fins or integrated microjets and fins.

It is difficult to achieve effective cooling at an affordable price because, due to physical constraints, liquids such as water must be used as a heat sink in combination with flow channels that provide large exchange surfaces and produce high heat transfer coefficients. Other building materials that provide high thermal conductivity should be used.

Another demanding requirement is that there must be direct contact between the electronic component and the cooling system (avoiding air spaces to guarantee sufficient thermal conductivity), while ensuring sufficient electrical insulation and avoiding mechanical stresses acting on the electronic component (for example, due to vibration or thermal expansion).

Other requirements, especially for automotive solutions, are that the coolant must transfer the received heat to the ambient air (via the vehicle radiator), which (in the worst case for which the system must be designed) can reach high temperatures (e.g. Dubai summer conditions). This leads to higher coolant temperature levels compared to non-automotive applications and therefore higher fluid flow rates required. Therefore, such cooling systems have a greater need for a low pressure drop design to avoid high pressure drops due to higher flow rates.

Due to increased safety and maintenance demands (compared to stationary installations), an automotive cooling solution has a greater need to be insensitive to debris. Additionally, it is necessary to design an automotive cooling system solution suitable for mass production.

Object of the invention

The invention provides an improved cooling body, which, being as compact as possible, allows for a more effective cooling structure and a simpler design.

Another object of the invention is to provide a cooling body, which meets the cooling demands of electronic components in the automotive sector as described above.

Summary of the invention

The invention relates to a cooling body, preferably designed to cool an electronic element, comprising a contact part comprising a contact surface for (thermal) contact with the part to be cooled and a base part separated from the contact part. by an intermediate piece between the contact piece and the base piece. The intermediate piece comprises separate or individual holes forming multiple rows of parallel arranged coolant tubes, whereby each tube extends substantially from the contact piece to the base piece. At least two coolant channels, the channels allowing a flow of coolant (preferably water is used as a coolant) from a coolant inlet to a coolant outlet, are formed by a sequence of parallel tubes connected by a surrounding surface of the piece of contact and an enveloping surface of the base part, such that each of the coolant channels extends several times from the contact part to the base part, and vice versa.

Preferably, the cooling body comprises five or more such coolant channels, for example, a number of five to ten coolant channels. As another preferred option, the surrounding surface of the contact piece and the base piece each comprise multiple projections arranged successively and spaced apart from each other on each surrounding surface, two successive projections together with part of the respective surrounding surface (and a face of end of the intermediate piece) forming a cavity or chamber, the cavity connecting a tube with the rear tube. For example, essentially a casing piece (base piece or contact piece) provides chambers between itself and the intermediate piece limiting projections through which two neighbors of the parallel tubes lead to each chamber, thus allowing an inlet and a reverse outlet. Preferably, the projections are made as fin-shaped structures. Such fin-shaped structures may have a straight shape, a wavy shape or a zigzag shape and are preferably arranged transversely to an extension direction of the base/contact piece.

Preferably, the subsequent rows of tubes are offset from each other (with respect to a general flow direction of each channel).

In embodiments with cavities as described above, each cavity optionally connects the outlets of all tubes in one row to all the inlets of the tubes in the subsequent row.

Preferably, the body is made of ceramic, preferably electrically insulating and thermally well conductive ceramic, such as, for example, aluminum oxide or aluminum nitride. Alternatively, the body is made of metal such as aluminum or copper.

In the case of a ceramic body, the body is optionally monolithic, preferably manufactured by sintering raw ceramic parts (raw material) of the base, intermediate and contact parts together in a single stage. Thus, additional assembly steps and thermal interfaces can be avoided.

As an option, the base part and the contact part are configured as parallel plates, whereby preferably an extension direction of the plates defines a general direction of the channels. As an additional option, the base part also serves as a contact part to contact the part to be cooled.

As a further option, the casing surface of the contact piece and the casing surface of the base piece are facing each other and/or the tubes are arranged at least approximately perpendicular to the casing surfaces.

In some embodiments, the base part and the contact part comprise stabilizing ribs and/or the contact surface is designed for direct attachment to the part to be cooled.

The invention also relates to a refrigerator, in particular, an electronic element refrigerator, specifically an automotive power electronic refrigerator, comprising a refrigerator body according to the invention.

The invention also relates to the use of a cooling body according to the invention in a power electronic system, in particular in a power electronic system for automobiles.

Brief description of the drawings

By way of example only, preferred embodiments of the invention will be described more fully below with reference to the accompanying figures, wherein:

Figures 1a to 1c show a first embodiment of the cooling body according to the invention;

Figure 2 shows another embodiment of parts of a refrigerator body.

Detailed description of the drawings

Figures 1a to 1c show a first embodiment of the cooling body 1 according to the invention, together with a part 100 to be cooled, for example, a power electronic element such as a MOS-FET or IGBT, in particular, as part of an electronic circuit of a car. As shown in Figure 1a in a 3D view, the cooling body 1 comprises three main parts, a contact part 2, an intermediate part 4 and a base part 3. Preferably, the electronic component 100 to be cooled comes into contact directly through the contact piece 2, for example, by a thermal adhesive, a thermal grease or some other interface material with high thermal conductivity.

The body 1 can be made of metal such as aluminum or copper, so the three parts 2, 3, 4 can be made from metal sheets joined together by welding or brazing. Bonding techniques such as sintering can also be used, whereby an intermediate sintering layer is used between the metal sheets. But, preferably, the body 1 is made of thermally conductive but electrically insulating ceramic, such as aluminum nitride or aluminum oxide, so there is advantageously no need for an additional electrical insulation layer. The body 1 is preferably a monolithic body 1. A monolithic ceramic body 1 is formed, for example, by manufacturing the three individual pieces 2, 3, 4 first as "raw" ceramic pieces and then sintering the three pieces 2, 3, 4 together in a single stage. Thus, additional assembly steps and thermal interfaces can be avoided. Alternatively, the base piece 3 and the contact piece 2 are manufactured from two layers of "green" ceramic instead of one. This would simplify the formation process of non-sintered ceramics. In this case, preferably some additional ribs are added to stabilize the structure. (Body 1, alternatively, can be metallic and insulation is added to cool the electronic components.)

The contact piece 2 and the base piece 3 are separated by the intermediate piece 4 between them. In the example, the contact part 2 and the base part 3 configured as long plates, arranged parallel to each other and extending in a direction S.

The intermediate piece 4 is made in the example as a block, shorter than the plates 2, 3 in the extension direction. The intermediate piece 4 is perforated, the holes 5u, 5d serving as coolant tubes. Thus, the intermediate piece 4 comprises a multitude of tubes 5u, 5d arranged parallel to each other. The tubes 5d, 5u extend from the facing surface 2s of the contact piece 2 to the facing surface 3s of the base piece 3, thus at least approximately perpendicular to the surface 2s and the surface 3s or the angle between the extension direction H of each hole 5u, 5d and the extension direction S of plates 2, 3 is a right angle (90°).

The three pieces 2, 3 and 4 are arranged in layers one above the other, forming in the example a sandwich-type structure. As an alternative to the sandwich structure shown in the example, where the two enveloping surfaces 2s, 3s are facing each other, the surfaces 2s, 3s are arranged at an angle, for example, orthogonal, to each other, or are "inverted" parallel to each other, the body 1 then forming a U-shaped structure. Consequently, the tubes 5d, 5u are then not straight as shown in Figure 1a, but are at an angle or have a "U" shape. ". As an option, the base part 4 is also configured as a contact part for thermal contact with the part to be cooled.

The surfaces 2s, 3s in front of the tubes 5d, 5u serve as surrounding surfaces. There is a small gap G between the intermediate piece 4 and the base piece 3, as well as between the intermediate piece 4 and the contact piece 2; or more precisely, there is a space G between each end of the tubes 5u, 5d and each surrounding surface 2s, 3s

Each space G is established by projections 2p, 3p distributed on each surrounding surface 2s, 3s. In other words, there are projections 2p, 3p on the inner side 2s, 3s of the contact plate 2 and the base plate 3 which serve as spacer supports with respect to the tube piece 4 in the center. Gaps G allow refrigerant to enter or exit in tubes 5u, 5d between outer pieces 2, 3 and inner piece 4.

According to the invention, the projections 2p, 3p are designed in such a way that they serve as barriers in the longitudinal direction S. Preferably, they are designed as fin-shaped structures, as shown.

To better see these fin-like protrusions, Figure 1b shows only the base plate 3s with fin-like structures 3p on the surrounding surface 3s. The fin-shaped structures 3p are arranged perpendicular to the extension direction S or the angle p between the extension direction P of each fin 3p and the extension direction S is a right angle or at least approximately 90°.

In the example, the fins 3p are made as straight fins. Alternatively, they are wave-shaped or zigzag-shaped. The height of the projections 3p defines the space G between the surrounding surface 3s and the tubes of the intermediate piece.

The fins 3p are arranged successively and (equally) spaced from each other on the surrounding surface 3s. The distance D between two successive projections 3p of a respective piece 2 or 3 is adapted to the diameter of the tubes so that it encompasses two successive tubes. The contact part 2 is designed accordingly, however, with an offset of (approximately) one tube (diameter) with respect to the base part 3, which is explained in more detail below.

Again with reference to Figure 1a, it can be seen that thus, two successive projections 2p or 3p together with the intermediate part of the respective surrounding surface 2s and 3s (and an end face of the intermediate piece 4) form a kind of chamber or cavity 6, with the end 7 of a tube 5d as the first opening and the end 8 of the next tube 5u as the second opening. In other words, the cavity 6 connects (the end 7 of) a tube 5u with (the end 8 of) the rear tube 5d.

According to the invention, the surrounding surfaces 2s, 3s or more particularly the cavities 6, connect the tubes 5u, 5d so that at least two coolant channels result, from a first tube 5d, extending several times from the contact piece. 2 to the base piece 3 and vice versa through the tubes 5u, 5d and cavities 6 between the tubes 5u, 5d. In the exemplary embodiment according to Figures 1a-1c, the projections 2p and therefore the "upper" cavities 6 in the contact piece 2 are at least one tube (diameter) offset - preferably offset by more than one diameter of tube- with respect to the projections 3p and therefore the "lower" cavities 6 in the base piece 3 in the extension direction S to achieve this result of directionally alternating channels. Said alternate channel C is illustrated in more detail in Figure 1c.

Figure 1c schematically illustrates in a 3D view said alternating coolant channel C according to the invention, indicated by the clear arrows inside the cooling body 1 (for ease of illustration, only one of the two or more channels is explicitly represented). A refrigerant (not shown) enters the refrigerator body 1 respectively through a channel C at an IN inlet (in the left side figure) in the extension direction 5 of the refrigerator body 1. The refrigerant is first directed to the inner surface or envelope 2s of the contact piece 2 (indicated by the first two left arrows), where the coolant takes heat from the contact piece 2 respectively from the electronics 100.

Then, due to a first projection 2p of the surrounding surface 2s of the contact part 2, the channel C first extends "downwards" from the contact part 2 to the base part 3 through a first tube 5d (indicated by the first dashed arrow from the left).

Then, there is a first base part cavity 6, formed by the surrounding surface 3s with two successive projections 3p of the base part 3, the cavity connecting the end of said first tube 5d with an end of the tube 5u that follows in the direction S. In other words, the outlet of the first tube 5d opens into the cavity 6 and the opening on the base side of the second tube 5u is the outlet of the cavity 6. In this way, the channel C is deflected by approximately 180 ° or, in other words, perform a U-turn (indicated by the first bent arrow). Thus, the refrigerant leaving the first tube 5d forms a flow that impinges on the surrounding surface 2s and enters the second tube 5u.

The channel C then extends backwards or "upwards" to the contact piece 2 according to the second tube 5u (indicated by the solid upward arrow). The "upwards" tube 5u leads to the cavity of the contact piece contact 6 into contact piece 2. Here, the coolant can again absorb heat from contact piece 2 or from electronics 100.

There again, channel C is redirected approximately 180° due to cavity 6, which leads to a second "downward" tube. In other words, the coolant now flows for the second time from the contact part 2 to the base part 3 through the next tube of the perforated intermediate part 4. As can be seen, the fin-like structures 2p, 3p of the outer parts 2, 3 separate the coolant between the holes and thus force the fluid to return to the next hole.

This "down and up" path from the contact part 2 to the base part 3 of the channels C is repeated several times (in the example five times). Accordingly, the structure of the coolant body 1 as suggested provides in a simple and compact manner channels C or refrigerant flow alternating multiple times between the contact piece 2 and the base piece 3 between the inlet IN and the outlet OUT. of the refrigerator body 1. The design allows for impact or shock coolant flow over the contact piece 2 (and the base piece 3) and a relatively large contact area between the coolant and the contact piece 2, respectively the 2s/3s surface for heat transfer.

Figure 2 shows another embodiment according to the invention. Shown, from a bird's eye view, is the base piece 2 and a cross section of the intermediate piece 4.

In this embodiment, several parallel channels C1, C2,...Cn with alternating direction between the contact piece 2 and the base piece 3 as described above are present, provided by the rows 5d1, 5u1, 5d2, 5u2, . .. 5dN of holes in the intermediate piece 4. The tube rows 5d1, 5u1, 5d2, 5u2, ... 5uN are separated in the extension direction (or general direction of coolant flow F) by side projections of the base 2p, extending along the entire width of the intermediate piece 4 in the P direction orthogonal to the S direction (in the same way, but the displaced separation of a tube is carried out by said lateral projections of the base, not shown in the figure 2).

Preferably, the difference between the total number of channels Cdtotal (IC n @ 5dn) in a given tube row, say 5dn and the total number of channels in the same tube row Ctotal (ICn@5un+i) is one. The difference between the total number of channels Ctotal (ICn@5dn) in a given tube row, say 5dn, and the total number of channels in the neighboring tube row Ctotal (ICn@5un) is also. However, the invention also works with the same number of channels.

Through the projections 2p, cavities 6a, 6b... 6n that connect rows of subsequent tubes 5u1, 5d2 for the redirection of each channel C1...Cn from "up" to "down". The coolant flow incident on the enveloping surface 2s is rotated each time and for each channel C1...Cn.

In the exemplary embodiment, the holes are offset in the S direction. In other words, only every second row of tubes 5d1...5dN is also located in the S direction. The coolant flowing, for example, into the chamber 6a by a tube in row 5u1, is distributed to the next two closest tubes in the next row 5d2 (indicated in the figure by the solid arrows Fc). This is also carried out on the base side (indicated in the figure by the dashed arrows Fb), that is, the same effect is observed on the base side.

Thus, a pipe of, for example, row 5u1 is not part of a single channel (for example, C1), but of two channels (C1 and C2). Due to the offset arrangement of the 5d1...5uN tube rows, each channel C1...Cn is assigned to more than one tube of each 5d1...5uN row. Therefore, the flow F of a coolant liquid not only alternates "up" and "down" as described with respect to Figures 1a-1c, but also alternates (in a much more limited way) in the "left" and "left" direction. "right". This tube or channel arrangement allows for a low turbulence flow F which allows for high heat transfer with a low pressure drop which improves heat absorption or coolant release.

Claims (15)

1. A cooling body (1), in particular, designed to cool an electronic element (100), comprising or a contact piece (2), which comprises a contact surface for contacting the piece to be cooled (100), or a base piece (3) separated from the contact piece (2), for example or an intermediate piece (4) between the contact piece (2) and the base piece (3), hence or the intermediate piece (4) comprises separate holes that form multiple rows of parallel arranged coolant tubes (5d, 5u, 5d1, 5u1, 5d2, 5u2-5dN), o each tube extends substantially from the contact piece (2) to the base piece (3) and o at least two, in particular at least five, parallel coolant channels (C, C1-Cn) are formed by sequences of parallel tubes (5d, 5u) connected by a surrounding surface (2s) of the contact piece (2) and a surrounding surface (3s) of the base piece (3) in such a way that the at least two coolant channels ( C, C1-Cn) each extends several times from the contact piece (2) to the base piece (3) and vice versa. 2. The cooling body (1) according to claim 1, characterized by The surrounding surface (2s) of the contact piece (2) and the surrounding surface (3s) of the base piece (3) each comprise multiple projections (2p, 3p) arranged successively and spaced apart from each other on each surrounding surface ( 2s, 3s), two successive projections (2p, 3p) together with part of the respective surrounding surface (2s, 3s) forming a cavity (6, 6a, 6b), the cavity (6, 6a, 6b) connecting a tube ( 5d, 5u) with the rear tube (5u, 5d). 3. The cooling body (1) according to claim 2, characterized by The projections (2p, 3p) are, in particular, straight, wavy and/or zig-zag, fin-shaped structures. 4. The cooling body (1) according to any of the preceding claims, characterized by The base piece (3) is configured as another contact surface to contact the piece to be cooled. 5. The cooling body (1) according to claim 2, characterized by each cavity (6a, 6b) connects the outputs of all the tubes of a row (5u1, 5d2, 5u2-5dN) with all the inputs of the tubes of the subsequent row (5d2, 5u2-5dN). 6. The cooling body (1) according to any of the preceding claims, characterized by the subsequent pipe rows (5d1, 5u1, 5d2, 5u2-5dN) are offset from each other. 7. The cooling body (1) according to any of the preceding claims, characterized by The body (1) is made of ceramics, in particular aluminum oxide or aluminum nitride. 8. The cooling body (1) according to claim 7, characterized by The body (1) is a monolithic body, in particular, formed by sintering raw ceramic parts of the base part, the intermediate part and the contact part together in a single step. 9. The cooling body (1) according to any of the preceding claims, characterized by the body (1) is made of metal, in particular aluminum or copper. 10. The cooling body (1) according to any of the preceding claims, characterized by the base piece (3) and the contact piece (2) are configured as parallel plates, in particular, where an extension direction (S) of the plates defines a general direction of the channels (C, C1-Cn) . 11. The cooling body (1) according to any of the preceding claims, characterized by or the surrounding surface (2s) of the contact piece (2) and the surrounding surface (3s) of the base piece (3) are facing each other and/or or the tubes (5d, 5u) are arranged at least approximately perpendicular to the surrounding surfaces (2s, 3s). 12. The cooling body (1) according to any of the preceding claims, characterized by The base piece (3) and the contact piece (2) comprise stabilizing ribs. 13. The refrigerator body (1) according to any of the preceding claims, characterized by The contact surface of the contact piece (2) is designed for direct attachment to the part to be cooled. 14. Refrigerator, in particular, an electronic element refrigerator, specifically an automotive power electronic refrigerator, comprising a refrigerator body (1) according to claim 1. 15. Use of a cooling body (1) according to claim 1 in a power electronics system, in particular, in a power electronics system for automobiles.